Field of the Invention
This invention relates to oven controllers for controlling temperature, duty cycle and time intervals. More specifically, it relates to a microprocessor whose function is dedicated as an oven controller by a read-only memory.
In the past, oven controllers have been simple electrical-mechanical devices consisting of a control for manually setting a temperature and another for setting a timer to sound an alarm when the desired time has elapsed. More sophisticated controllers permitted setting a time for the oven to start and a time for the oven to stop, automatically.
With the advent of the microwave oven, the problem of controlling the operation became somewhat more complex. For example, the duty cycle of the magnetron which produces the microwaves for cooking should be one value for thawing and another for cooking a non-frozen item with a variance also required for the different kinds of items to be cooked. For example, to bake potatoes may require a different magnetron duty cycle than to bake a turkey. In prior art oven controllers, the duty cyle is manually controlled by simply referring to a cook book provided by the oven manufacturer to obtain a listed duty cycle and then simply setting a dial according to the listed duty cycle.
More modern microwave oven controllers utilize solid state electronic techniques for the control circuitry, such circuitry dedicated to the particular purpose. That is, if a new function is desired, new circuitry must be designed and implemented to achieve that new function. The prior art has progressed to the point where time and duty cycle may be set to operate in a so-called time mode.